Phase 2 Results Indicate Evenamide, A Selective Modulator of Glutamate Release, Is Associated With Clinically Important Long-Term Efficacy When Added to an Antipsychotic in Patients With Treatment-Resistant Schizophrenia.

Results from a pilot, 6-week, randomized, open-label, rater-blinded study, with 46-week extension, indicate very good tolerability with exceptional, clinically important, increasing efficacy of evenamide (7.5, 15, and 30 mg bid), a glutamate modulator, as add-on treatment to antipsychotics in 161 treatment-resistant, schizophrenia patients. Ninety-five percent of patients completed 6 weeks (1 discontinued for adverse event), and 89% continued in the extension. Results from the first 100 patients enrolled showed very low attrition over 1 year (77 completers); data pooled from all dose groups showed the Positive and Negative Syndrome Scale total score improved significantly (P < .001; paired t test; last observation carried forward [LOCF]) from baseline at 6 weeks (-9.4), 6 months (-12.7), and 1 year (-14.7); similarly, the proportion of responders (≥20% improvement) increased over time from 6 weeks (16.5%) to 6 months (39%) to 1 year (47.4%). Noteworthy improvement was also observed at each timepoint on the Clinical Global Impression - Severity scale and Clinical Global Impression of Change, indicating progressively increasing efficacy of evenamide up to 1 year.

Persistent autism-relevant behavioral phenotype and social neuropeptide alterations in female mice offspring induced by maternal transfer of PBDE congeners in the commercial mixture DE-71.

Polybrominated diphenyl ethers (PBDEs) are ubiquitous persistent organic pollutants (POPs) that are known neuroendocrine disrupting chemicals with adverse neurodevelopmental effects. PBDEs may act as risk factors for autism spectrum disorders (ASD), characterized by abnormal psychosocial functioning, although direct evidence is currently lacking. Using a translational exposure model, we tested the hypothesis that maternal transfer of a commercial mixture of PBDEs, DE-71, produces ASD-relevant behavioral and neurochemical deficits in female offspring. C57Bl6/N mouse dams (F0) were exposed to DE-71 via oral administration of 0 (VEH/CON), 0.1 (L-DE-71) or 0.4 (H-DE-71) mg/kg bw/d from 3 wk prior to gestation through end of lactation. Mass spectrometry analysis indicated in utero and lactational transfer of PBDEs (in ppb) to F1 female offspring brain tissue at postnatal day (PND) 15 which was reduced by PND 110. Neurobehavioral testing of social novelty preference (SNP) and social recognition memory (SRM) revealed that adult L-DE-71 F1 offspring display deficient short- and long-term SRM, in the absence of reduced sociability, and increased repetitive behavior. These effects were concomitant with reduced olfactory discrimination of social odors. Additionally, L-DE-71 exposure also altered short-term novel object recognition memory but not anxiety or depressive-like behavior. Moreover, F1 L-DE-71 displayed downregulated mRNA transcripts for oxytocin (Oxt) in the bed nucleus of the stria terminalis (BNST) and supraoptic nucleus, and vasopressin (Avp) in the BNST and upregulated Avp1ar in BNST, and Oxtr in the paraventricular nucleus. Our work demonstrates that developmental PBDE exposure produces ASD-relevant neurochemical, olfactory processing and behavioral phenotypes that may result from early neurodevelopmental reprogramming within central social and memory networks.

Acute intranasal osteopontin treatment in male rats following TBI increases the number of activated microglia but does not alter lesion characteristics.

Intranasal recombinant osteopontin (OPN) has been shown to be neuroprotective in different models of acquired brain injury but has never been tested after traumatic brain injury (TBI). We used a model of moderate-to-severe controlled cortical impact in male adult Sprague Dawley rats and tested our hypothesis that OPN treatment would improve neurological outcomes, lesion and brain tissue characteristics, neuroinflammation, and vascular characteristics at 1 day post-injury. Intranasal OPN administered 1 hr after the TBI did not improve neurological score, lesion volumes, blood-brain barrier, or vascular characteristics. When assessing neuroinflammation, we did not observe any effect of OPN on the astrocyte reactivity but discovered an increased number of activated microglia within the ipsilateral hemisphere. Moreover, we found a correlation between edema and heme oxygenase-1 (HO-1) expression which was decreased in OPN-treated animals, suggesting an effect of OPN on the HO-1 response to injury. Thus, OPN may increase or accelerate the microglial response after TBI, and early response of HO-1 in modulating edema formation may limit the secondary consequences of TBI at later time points. Additional experiments and at longer time points are needed to determine if intranasal OPN could potentially be used as a treatment after TBI where it might be beneficial by activating protective signaling pathways.

Exosomes in Alzheimer's Disease: Potential Role as Pathological Mediators, Biomarkers and Therapeutic Targets.

The concept of exosomes has been progressively changed from the status of cellular trashcans to multitasking organelles involved in many processes, including internalization, transport and transfer of macromolecules such as proteins, lipids and nucleic acids. While underpinning the mechanisms behind neurodegeneration and neuronal loss, exosomes were shown to be involved in carrying pathological misfolded proteins, propagation of ß-amyloid protein and hyper-phosphorylated tau proteins across the brain that ultimately leads to the onset of Alzheimer's disease (AD), the most prevailing multifactorial neurodegenerative disorder. A potential novel therapeutic role of exosomes in AD intervention is suggested by their ability to increase Aß clearance. This review aims to highlight the important pathological mechanisms as well as therapeutic strategies involving exosomes towards AD prevention.

Repeated isoflurane in adult male mice leads to acute and persistent motor decrements with long-term modifications in corpus callosum microstructural integrity.

Isoflurane is a commonly used inhalational anesthetic, clinically and in animal experimental studies. Although it has been reported as safe, recent findings suggest that despite widespread use, isoflurane-induced inhalational anesthesia can lead to various pathophysiological and cognitive alterations. Therefore, we aimed to investigate the long-term behavioral and white matter consequences of repeated isoflurane exposure. Twenty 3-month-old C57BL/6J male mice received one exposure of isoflurane for 40 min or 2 exposures to isoflurane separated by 3 days. Behavioral paradigms (open field, balance beam, foot fault, rotarod, elevated zero maze, tail suspension, water maze, and social recognition tests) were administered at 1, 3, 5, 7, and 90 days post exposure. Animals exposed to repeated isoflurane showed significant motor deficits on the balance beam and increased anxiety-like behavior. Animals exposed to single isoflurane showed impaired performance on the foot fault test. Diffusion tensor imaging showed that repeated isoflurane exposure led to long-term disruption of water diffusivity in corpus callosum (CC) white matter. Furthermore, 2-D structure-tensor analysis from stained brain sections showed differences in the microstructural organization of CC white matter in mice with single versus repeated isoflurane exposures. These results suggest that behavioral deficits observed up to 90 days after repeated isoflurane exposure resulted from, at least in part, altered CC white matter microstructural integrity.

Using animal models to evaluate the functional consequences of anesthesia during early neurodevelopment.

Fifteen years ago Olney and colleagues began using animal models to evaluate the effects of anesthetic and sedative agents (ASAs) on neurodevelopment. The results from ongoing studies indicate that, under certain conditions, exposure to these drugs during development induces an acute elevated apoptotic neurodegenerative response in the brain and long-term functional impairments. These animal models have played a significant role in bringing attention to the possible adverse effects of exposing the developing brain to ASAs when few concerns had been raised previously in the medical community. The apoptotic degenerative response resulting from neonatal exposure to ASAs has been replicated in many studies in both rodents and non-human primates, suggesting that a similar effect may occur in humans. In both rodents and non-human primates, significantly increased levels of apoptotic degeneration are often associated with functional impairments later in life. However, behavioral deficits following developmental ASA exposure have not been consistently reported even when significantly elevated levels of apoptotic degeneration have been documented in animal models. In the present work, we review this literature and propose a rodent model for assessing potential functional deficits following neonatal ASA exposure with special reference to experimental design and procedural issues. Our intent is to improve test sensitivity and replicability for detecting subtle behavioral effects, and thus enhance the translational significance of ASA models.

Pomegranate supplementation improves cognitive and functional recovery following ischemic stroke: A randomized trial.

Objectives: We tested whether supplementing with pomegranate polyphenols can enhance cognitive/functional recovery after stroke. Methods: In this parallel, block-randomized clinical trial, we administered commercially-available pomegranate polyphenol or placebo pills twice per day for one week to adult inpatients in a comprehensive rehabilitation setting starting approximately 2 weeks after stroke. Pills contained 1 g of polyphenols derived from whole pomegranate, equivalent to levels in approximately 8 oz of juice. Placebo pills were similar to the pomegranate pills except that they contained only lactose. Of the 163 patients that were screened, 22 were eligible and 16 were randomized (8 per group). We excluded one subject per group from the neuropsychological analyses since they were lost to follow-up, but we included all subjects in the analysis of functional data since outcome data were available. Clinicians and subjects were blinded to group assignment. Neuropsychological testing (primary outcome: Repeatable Battery for the Assessment of Neuropsychological Status) and functional independence scores were used to determine changes in cognitive and functional ability. Results: Pomegranate-treated subjects demonstrated more neuropsychological and functional improvement and spent less time in the hospital than placebo controls. Discussion: Pomegranate polyphenols enhanced cognitive and functional recovery after stroke, justifying pursuing larger clinical trials.

Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat.

Hypoxic-ischemic encephalopathy (HIE) resulting from asphyxia is the most common cause of neonatal brain damage and results in significant neurological sequelae, including cerebral palsy. The current therapeutic interventions are extremely limited in improving neonatal outcomes. The present study tests the hypothesis that the suppression of endogenous glucocorticoid receptors (GRs) in the brain increases hypoxic-ischemic (HI) induced neonatal brain injury and worsens neurobehavioral outcomes through the promotion of increased inflammation. A mild HI treatment of P9 rat pups with ligation of the right common carotid artery followed by the treatment of 8% O2 for 60 min produced more significant brain injury with larger infarct size in female than male pups. Intracerebroventricular injection of GR siRNAs significantly reduced GR protein and mRNA abundance in the neonatal brain. Knockdown of endogenous brain GRs significantly increased brain infarct size after HI injury in male, but not female, rat pups. Moreover, GR repression resulted in a significant increase in inflammatory cytokines TNF-α and IL-10 at 6 h after HI injury in male pups. Male pups treated with GR siRNAs showed a significantly worsened reflex response and exhibited significant gait disturbances. The present study demonstrates that endogenous brain GRs play an important role in protecting the neonatal brain from HI induced injury in male pups, and suggests a potential role of glucocorticoids in sex differential treatment of HIE in the neonate.

Recombinant Osteopontin Stabilizes Smooth Muscle Cell Phenotype via Integrin Receptor/Integrin-Linked Kinase/Rac-1 Pathway After Subarachnoid Hemorrhage in Rats.

BACKGROUND AND PURPOSE: Recombinant osteopontin (rOPN) has been reported to be neuroprotective in stroke animal models. The purpose of this study is to investigate a potential role and mechanism of nasal administration of rOPN on preserving the vascular smooth muscle phenotype in early brain injury after subarachnoid hemorrhage (SAH). METHODS: One hundred and ninety-two male adult Sprague-Dawley rats were used. The SAH model was induced by endovascular perforation. Integrin-linked kinase small interfering RNA was intracerebroventricularly injected 48 hours before SAH. The integrin receptor antagonist fibronectin-derived peptide Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP), focal adhesion kinase inhibitor Fib-14, and Rac-1 inhibitor NSC23766 were administered 1 hour before SAH induction. rOPN was administered via the intracerebroventricular and nasal route after SAH. SAH grade, neurological scores, brain water content, brain swelling, hematoxylin and eosin staining, India ink angiography, Western blots, and immunofluorescence were used to study the mechanisms of rOPN on the vascular smooth muscle phenotypic transformation. RESULTS: The marker proteins of vascular smooth muscle phenotypic transformation α-smooth muscle actin decreased and embryonic smooth muscle myosin heavy chain (SMemb) increased significantly at 24 and 72 hours in the cerebral arteries after SAH. rOPN prevented the changes of α-smooth muscle actin and SMemb and significantly alleviated neurobehavioral dysfunction, increased the cross-sectional area and the lumen diameter of the cerebral arteries, reduced the brain water content and brain swelling, and improved the wall thickness of cerebral arteries. These effects of rOPN were abolished by GRGDSP, integrin-linked kinase small interfering RNA, and NSC23766. Intranasal application of rOPN at 3 hours after SAH also reduced neurological deficits. CONCLUSIONS: rOPN prevented the vascular smooth muscle phenotypic transformation and improved the neurological outcome, which was possibly mediated by the integrin receptor/integrin-linked kinase/Rac-1 pathway.

Inhibition of microRNA-210 provides neuroprotection in hypoxic-ischemic brain injury in neonatal rats.

Perinatal hypoxic-ischemic encephalopathy (HIE) is associated with high neonatal mortality and severe long-term neurologic morbidity. Yet the mechanisms of brain injury in infants with HIE remain largely elusive. The present study determined a novel mechanism of microRNA-210 (miR-210) in silencing endogenous neuroprotection and increasing hypoxic-ischemic brain injury in neonatal rats. The study further revealed a potential therapeutic effect of miR-210 inhibition using complementary locked nucleic acid oligonucleotides (miR-210-LNA) in 10-day-old neonatal rats in the Rice-Vannucci model. The underlying mechanisms were investigated with intracerebroventricular injection (i.c.v) of miR-210 mimic, miR-210-LNA, glucocorticoid receptor (GR) agonist and antagonist. Luciferase reporter gene assay was conducted for identification of miR-210 targeting GR 3'untranslated region. The results showed that the HI treatment significantly increased miR-210 levels in the brain, and miR-210 mimic significantly decreased GR protein abundance and exacerbated HI brain injury in the pups. MiR-210-LNA administration via i.c.v. 4h after the HI insult significantly decreased brain miR-210 levels, increased GR protein abundance, reduced HI-induced neuronal death and brain infarct size, and improved long-term neurological function recovery. Of importance, the intranasal delivery of miR-210-LNA 4h after the HI insult produced similar effects in decreasing HI-induced neonatal brain injury and improving neurological function later in life. Altogether, the present study provides evidence of a novel mechanism of miR-210 in a neonatal HI brain injury model, and suggests a potential therapeutic approach of miR-210 inhibition in the treatment of neonatal HIE.

Platelet-Derived Growth Factor Receptor-ß Regulates Vascular Smooth Muscle Cell Phenotypic Transformation and Neuroinflammation After Intracerebral Hemorrhage in Mice.

OBJECTIVE: Platelet-derived growth factor-BB activates platelet-derived growth factor receptor-ß and promotes vascular smooth muscle cell phenotypic transformation. Elevated levels of non-muscle myosin IIB (SMemb) are found in secretory smooth muscle cells along with inflammatory mediators, such as intercellular adhesion molecule-1, which can amplify neutrophil infiltration into the brain. In the present study, we investigated the role of platelet-derived growth factor-BB/platelet-derived growth factor receptor-ß following intracerebral hemorrhage-induced brain injury in mice, with emphasis on its ability to promote vascular smooth muscle cell phenotypic transformation followed by increased intercellular adhesion molecule-1 expression and elevated neutrophil infiltration in the vicinity of the hematoma. We also determined the extent to which plasmin from the hematoma influences the platelet-derived growth factor-BB/platelet-derived growth factor receptor-ß system subsequent to intracerebral hemorrhage. DESIGN: Controlled in vivo laboratory study. SETTING: Animal research laboratory. SUBJECTS: One hundred and fifty six eight-week-old male CD1 mice. INTERVENTIONS: Brain injury was induced by autologous arterial blood or plasmin injection into mouse brains. Small interfering RNA targeting platelet-derived growth factor receptor-ß was administered 24 hours before intracerebral hemorrhage. A platelet-derived growth factor receptor antagonist, Gleevec, was administered following intracerebral hemorrhage. A mitogen-activated protein kinase-activated protein kinase 2 inhibitor (KKKALNRQLGVAA) was delivered with platelet-derived growth factor-BB in naïve animals. Platelet-derived growth factor-BB was injected with a plasmin inhibitor (ε-aminocaproic acid) in intracerebral hemorrhage mice. Plasmin-injected mice were given platelet-derived growth factor receptor-ß small interfering RNA 24 hours before the operation. Neurological deficits, brain edema, western blots, and immunofluorescence were evaluated. MEASUREMENTS AND MAIN RESULTS: Platelet-derived growth factor receptor-ß small interfering RNA attenuated SMemb and intercellular adhesion molecule-1 expression and neutrophil infiltration at 24 hours post injury and reduced neurological deficits and brain edema at 24 and 72 hours following intracerebral hemorrhage. The platelet-derived growth factor receptor antagonist, Gleevec, reduced SMemb and intercellular adhesion molecule-1 expression. Platelet-derived growth factor receptor-ß activation led to increased expression of intercellular adhesion molecule-1 and was reversed by KKKALNRQLGVAA in naïve mice. Plasmin inhibition suppressed platelet-derived growth factor receptor-ß activation and neutrophil infiltration, whereas exogenous platelet-derived growth factor-BB increased platelet-derived growth factor receptor-ß activation, regardless of plasmin inhibition. Platelet-derived growth factor receptor-ß small interfering RNA decreased the expression of intercellular adhesion molecule-1 by plasmin injection. CONCLUSION: The platelet-derived growth factor-BB/platelet-derived growth factor receptor-ß system contributes to neuroinflammation through vascular smooth muscle cell phenotypic transformation near the hematoma via the p38 mitogen-activated protein kinase/mitogen-activated protein kinase-activated protein kinase 2 pathway following intracerebral hemorrhage. Plasmin is hypothesized to be upstream of the proposed neuroinflammatory system. The therapeutic intervention targeting the platelet-derived growth factor-BB/platelet-derived growth factor receptor-ß is a novel strategy to prevent plasmin-induced brain injury following intracerebral hemorrhage.

Patterns of Behavioral Deficits in Rodents Following Brain Injury Across Species, Gender, and Experimental Model.

Behavioral data were collected from several hundred mice and rats using a variety of experimental models of brain injury. The use of consistent protocols allowed compilation of these data, facilitating analyses of animal behaviors across experimental models, species, and gender. Spatial learning and sensorimotor/coordination data are presented, suggesting that, in general, rats performed better than mice both in the water maze and on the rotarod. Compared with females, males performed slightly better in the water maze and slightly worse on the rotarod. However, gender by species interactions accounted for both of these differences. Male rats performed better in the water maze than female rats, male mice, and female mice, which did not differ. Male mice performed worse on the rotarod than female mice, male rats, and female rats, which performed similarly. Furthermore, animals with subcortical injury were impaired in the water maze, but performed better than animals with cortical injuries. However, only animals with cortical injuries were impaired on the rotarod. Additional covariates, such as edema and lesion size, may further clarify these phenotypes. Overall, we provide evidence that abbreviated test batteries can be specifically designed to test deficits, depending on the species, gender, and model.

Rat globus pallidus neurons: functional classification and effects of dopamine depletion.

The rat globus pallidus (GP) is homologous to the primate GP externus. Studies with injectable anesthetics suggest that GP neurons can be classified into Type-I and Type-II cells based on extracellularly recorded spike shape, or positively coupled (PC), negatively coupled (NC), and uncoupled (UC) cells based on functional connectivity with the cortex. In this study, we examined the electrophysiology of rat GP neurons using the inhalational anesthetic isoflurane which offers more constant and easily regulated levels of anesthesia than injectable anesthetics. In 130 GP neurons recorded using small-tip glass electrodes (<1 µm), all but one fired Type-II spikes (positive/negative waveform). Type-I cells were unlikely to be inhibited by isoflurane since all GP neurons also fired Type-II spikes under ketamine-induced anesthesia. When recorded with large-tip electrodes (∼2 µm), however, over 70% of GP neurons exhibited Type-I spikes (negative/positive waveform). These results suggest that the spike shape, recorded extracellularly, varies depending on the electrode used and is not reliable in distinguishing Type-I and Type-II neurons. Using dual-site recording, 40% of GP neurons were identified as PC cells, 17.5% NC cells, and 42.5% UC cells. The three subtypes also differed significantly in firing rate and pattern. Lesions of dopamine neurons increased the number of NC cells, decreased that of UC cells, and significantly shifted the phase relationship between PC cells and the cortex. These results support the presence of GP neuron subtypes and suggest that each subtype plays a different role in the pathophysiology of Parkinson's disease. Synapse 69:41-51, 2015. © 2014 Wiley Periodicals, Inc.

Inhibition of transforming growth factor-ß attenuates brain injury and neurological deficits in a rat model of germinal matrix hemorrhage.

BACKGROUND AND PURPOSE: Transforming growth factor-ß (TGF-ß) overproduction and activation of the TGF-ß pathway are associated with the development of brain injury following germinal matrix hemorrhage (GMH) in premature infants. We examined the effects of GMH on the level of TGF-ß1 in a novel rat collagenase-induced GMH model and determined the effect of inhibition of the TGF receptor I. METHODS: In total, 92 seven-day old (P7) rats were used. Time-dependent effects of GMH on the level of TGF-ß1 and TGF receptor I were evaluated by Western blot. A TGF receptor I inhibitor (SD208) was administered daily for 3 days, starting either 1 hour or 3 days after GMH induction. The effects of GMH and SD208 on the TGF-ß pathway were evaluated by Western blot at day 3. The effects of GMH and SD208 on cognitive and motor function were also assessed. The effects of TGF receptor I inhibition by SD208 on GMH-induced brain injury and underlying molecular pathways were investigated by Western blot, immunofluorescence, and morphology studies 24 days after GMH. RESULTS: GMH induced significant delay in development, caused impairment in both cognitive and motor functions, and resulted in brain atrophy in rat subjects. GMH also caused deposition of both vitronectin (an extracellular matrix protein) and glial fibrillary acidic protein in perilesion areas, associated with development of hydrocephalus. SD208 ameliorated GMH-induced developmental delay, improved cognitive and motor functions, and attenuated body weight loss. SD208 also decreased vitronectin and glial fibrillary acidic protein deposition and decreased GMH-induced brain injury. CONCLUSIONS: Increased level of TGF-ß1 and activation of the TGF-ß pathway associate with the development of brain injury after GMH. SD208 inhibits GMH-induced activation of the TGF-ß pathway and leads to an improved developmental profile, partial recovery of cognitive and motor functions, and attenuation of GMH-induced brain atrophy and hydrocephalus.

Reparative effects of neural stem cells in neonatal rats with hypoxic-ischemic injury are not influenced by host sex.

BACKGROUND: Gender is increasingly recognized as an important influence on brain development, disease susceptibility, and response to pharmacologic/rehabilitative treatments. In regenerative medicine, it remains entirely unknown whether there is an interaction between transplanted stem cells and host gender that might bias efficacy and safety in some patients but not others. METHODS: We examined the role of recipient gender in a neonatal rat hypoxic-ischemic injury (HII) model, treated with female human neuronal stem cells (hNSCs), labeled with superparamagnetic iron oxide particles implanted into the contralateral cerebral ventricle. We monitored HII evolution (by magnetic resonance imaging, histopathology, behavioral testing) and hNSC fate (migration, replication, viability). RESULTS: Recipient gender after implantation did not influence the volume or location of ischemic injury (1, 30, or 90 d) or behavior (90 d). Superparamagnetic iron oxide labeling did not influence HII evolution. Implantation had its greatest benefit on mild/moderate injuries, which remained stable rather than increasing as in severe HII as is the natural history for such lesions. CONCLUSION: Our results suggest that hNSC treatment (including using hNSCs that are prelabeled with iron to allow tracking in real time by magnetic resonance imaging) would be equally safe and effective for male and female human newborns with mild-to-moderate HII.

Global analysis of Twitter communication in corporate social responsibility area: sustainability, climate change, and waste management.

Many people now consider social media to be an integral part of their daily routines, which has enabled companies to implement successful corporate social responsibility campaigns through these platforms. The direct interaction with stakeholders offered by social media helps companies to build understanding, trust, and their image. The aim of this study was to identify key topics and trends communicated in connection with corporate social responsibility on the Twitter social network from 2017 to 2022. Analysis of 520,638 tweets by 168,134 unique users identified a predominance of environment-related topics: Sustainability, Climate Change, and Waste management. However, Charity remains the largest single topic. Based on the trend analysis, the areas of ESG, Social Impact, and Charity were identified as growth areas in communication, while Green and Philanthropy, on the other hand, were identified as decreasing.

Long-term magnetic resonance imaging of stem cells in neonatal ischemic injury.

OBJECTIVE: Quantitative magnetic resonance imaging (MRI) can serially and noninvasively assess the degree of injury in rat pup models of hypoxic ischemic injury (HII). It can also noninvasively monitor stem cell migration following iron oxide prelabeling. Reports have shown that neural stem cells (NSCs) may help mediate neuroprotection or stimulate neuroreparative responses in adult and neonatal models of ischemic injury. We investigated the ability of high-field MRI to monitor and noninvasively quantify the migration, proliferation, and location of iron oxide-labeled NSCs over very long time periods (58 weeks) in real time while contemporaneously correlating this activity with the evolving severity and extent of neural damage. METHODS: Labeled clonal murine NSCs (mNSCs) were implanted 3 days after unilateral HII in 10-day-old rat pups into the contralateral striatum or ventricle. We developed methods for objectively quantifying key aspects of dynamic NSC behavior (eg, viability; extent, and speed of migration; degree of proliferation; extent of integration into host parenchyma). MRI images were validated with histological and immunohistochemical assessments. RESULTS: mNSCs rapidly migrated (100 µm/day) to the lesion site. Chains of migrating NSCs were observed in the corpus callosum. In pups subjected to HII, though not in intact control animals, we observed a 273% increase in the MR-derived volume of mNSCs 4 weeks after implantation (correlating with the known proliferative behavior of endogenous and exogenous NSCs) that slowly declined over the 58-week time course, with no adverse consequences. Large numbers of now quiescent mNSCs remained at the site of injury, many retaining their iron oxide label. INTERPRETATION: Our studies demonstrate that MRI can simultaneously monitor evolving neonatal cerebral injury as well as NSC migration and location. Most importantly, it can noninvasively monitor proliferation dynamically for prolonged time periods. To be able to pursue clinical trials in newborns using stem cell therapies it is axiomatic that safety be insured through the long-term real time monitoring of cell fate and activity, particularly with regard to observing unanticipated risks to the developing brain. This study supports the feasibility of reliably using MRI for this purpose.

Osteopontin reduced hypoxia-ischemia neonatal brain injury by suppression of apoptosis in a rat pup model.

BACKGROUND AND PURPOSE: Osteopontin (OPN) is neuroprotective in ischemic brain injuries in adult experimental models; therefore, we hypothesized that OPN would provide neuroprotection and improve long-term neurological function in the immature brain after hypoxic-ischemic (HI) injury. METHODS: HI was induced by unilateral ligation of the right carotid artery followed by hypoxia (8% O(2) for 2 hours) in postnatal Day 7 rats. OPN (0.03 µg or 0.1 µg) was injected intracerebroventricularly at 1 hour post-HI. Temporal expression of endogenous OPN was evaluated in the normal rat brain at the age of 0, 4, 7, 11, 14, and 21 days and in the ipsilateral hemisphere after HI. The effects of OPN were evaluated using 2-3-5-triphenyl tetrazolium chloride staining, apoptotic cell death assay, and cleaved caspase-3 expression. Neurological function was assessed by the Morris water maze test. RESULTS: Endogenous OPN expression in the brain was the highest at the age of 0 day with continuous reduction until the age of 21 days during development. After HI injury, endogenous OPN expression was increased and peaked at 48 hours. Exogenous OPN decreased infarct volume and improved neurological outcomes 7 weeks after HI injury. OPN-induced neuroprotection was blocked by an integrin antagonist. CONCLUSIONS: OPN-induced neuroprotection was associated with cleaved-caspase-3 inhibition and antiapoptotic cell death. OPN treatment improved long-term neurological function against neonatal HI brain injury.

Effects of hemodilution after traumatic brain injury in juvenile rats.

BACKGROUND: Normovolemic hemodilution (HD) in adult animal studies has shown exacerbation of traumatic brain injury (TBI) lesion volumes. Similar studies in juvenile rats have not been reported and outcomes are likely to be different. This study investigated the effects of normovolemic hemodilution (21% hematocrit) in a juvenile TBI (jTBI) model. METHODS: Twenty 17-day-old rats underwent moderate cortical contusion impact injury (CCI) and were divided into four groups: CCI/hemodilution (HD) (group HD), CCI/no HD (group C), Sham/HD (group SHD), and Sham/no HD (group S). Regional laser Doppler flowmetry (LDF), edema formation (MRI-T2WI), water mobility assessed using diffusion weighted imaging (MRI-DWI), open field activity tests, and histological analyses were evaluated for lesion characteristics. RESULTS: Hemodilution significantly increased blood flow in the HD compared to the C group after TBI. T2WI revealed a significantly increased extravascular blood volume in HD at 1, 7, and 14 days post-CCI. Edematous tissue and total contusional lesion volume were higher in HD-treated animals at 1 and 14 days. DWI revealed that HD, SHD, and C groups had elevated water mobility compared to S groups in the ipsilateral cortex and striatum. Histology showed a larger cortical lesion in the C than HD group. Open field activity was increased in HD, C, and SHD groups compared to the S group. CONCLUSIONS: Hemodilution results in significant brain hyperemia with increased edema formation, extravascular blood volume, and water mobility after jTBI. Hemodilution results in less cortical damage but did not alter behavior. Hemodilution is likely not to be clinically beneficial following jTBI.

Neuroprotection by melatonin after germinal matrix hemorrhage in neonatal rats.

BACKGROUND: Germinal matrix hemorrhage (GMH) is a devastating neurological disorder of very low birth weight premature infants that leads to post-hemorrhagic hydrocephalus, cerebral palsy, and mental retardation. Melatonin is a potent antioxidant known to reverse free-radical mediated injury in the brain. This study investigated the effect of melatonin treatment after GMH injury. METHODS: Clostridial collagenase was infused into the right germinal matrix region of neonatal rats with stereotaxic technique. Cognitive function, sensorimotor ability, cerebral, cardiac and splenic growths were measured in juvenile animals. RESULTS: Systemic melatonin treatment ameliorated cognitive and sensorimotor dysfunction at the juvenile developmental stage. This hormone also normalized brain atrophy, splenomegaly, and cardiac hypertrophy consequences at 1 month after injury. CONCLUSION: This study supports the role of free radicals in acute neonatal hemorrhagic brain injury. Melatonin is an effective antioxidant that can protect the infant's brain from the post-hemorrhagic consequences of mental retardation and cerebral palsy. Further mechanistic studies are warranted to determine the mechanisms behind these neuroprotective effects.